Which taxonomic classification level is the largest or most broad

The largest or most broad taxonomic classification level is the "Kingdom" level.

The largest or most broad taxonomic classification level is the kingdom. In the Linnaean system of taxonomy, living organisms are classified into several levels: kingdom, phylum, class, order, family, genus, and species. The kingdom level is the highest and broadest level of classification, grouping organisms into five main categories: animals (Animalia), plants (Plantae), fungi (Fungi), protists (Protista), and prokaryotes (Monera).